My little cousin's name is Kiersten and I think it's a really cute name! Her middle name is Jean after our grandma. Kiersten is a feminine name and I think it works on someone of any age, from a newborn baby to an old lady! That's one of the reasons why I like it.
Despite the Christian meaning, I like this name. It comes off as a cool, pretty name of a spunky, smart girl, and it works for grown-ups, which is important. Plus, this spelling makes it clear that the name should be pronounced KEER-sten, not KUR-sten. The name has simply become too common.